Having the intention or power to bring about salvation or redemption.
“…the invisible Godhead is indeed shown in creation, but…we have no eyes to see until they are enlightened through faith by the inner revelation from God…no sooner do we gain some slight knowledge of God from looking at the world, than we turn from the true God and set up in his place an imaginary vision from our own brain. We draw the worship of justice, wisdom and goodness away from the fountain-head, transferring it elsewhere. Even more, by the wrong assessments we make, we either obscure or pervert God’s creation so that we rob it of its glory and withhold the praise due him…So, since the radiance which meets our vision, both in the heavens and on the earth, makes man’s ingratitude unforgivable, and because God has given us all the same opportunity of seeing his deity reflected in creation in order to bring the whole human race under the same condemnation, something different and better is needed to lead us to our Creator God. To this end he has added the light of his Word to make himself known in salvation…”
Calvin sums up well the exclusivist position on salvation. The Word of God, in written or spoken form, is absolutely essential for the salvation of anyone. While some knowledge of God is available through creation, there is no salvific knowledge available through creation. Accordingly, there are no faiths apart from Christianity that can lead to salvation.